Optimism is associated with charisma and being seen as a leader. Optimists are great at spotting and exploiting opportunities. However, optimists tend to avoid thinking about the things that could go wrong, leading many experts to believe that overoptimism is the most dangerous position your company can take.

That’s why your team also needs pessimists: specifically, defensive pessimists. Unlike true pessimists, who never believe anything’s going to work, defensive pessimists gain comfort from thinking about all the ways things can go sideways, and then making plans to avoid or overcome those difficulties. They tend to have a higher baseline level of anxiety than optimists, but perform their job every bit as well.

When presented with a proposal or a new idea, optimists and pessimists face different challenges with long-term political implications:

• If you reflexively say “yes” or immediately volunteer your support, you get to be the hero in the moment. But an unspoken question lingers in the air: can you deliver? If the project’s a dog, you reduce your social capital with the group, not to mention stress yourself out trying to save it. And even if the leader appreciates your can-do spirit in the short term, if you aren’t willing to shoot straight with them when necessary, their trust in you will erode over time.
• If you reflexively say “no” or bring up objections, you may sound really smart in the moment and get people nodding along with your sage insight. But doing it too much or too often can be bad for your company’s culture. Raising objections too early on new ideas squashes creative thinking and inhibits participation, and can hamstring psychological safety, which is critical to team effectiveness. Over time, creativity and innovation suffer as fewer people speak up, and that can put you at a real competitive disadvantage.

So what’s a conscientious leader to do?

1. Mix it up. For best results, stack your teams with a mix of optimists and defensive pessimists. If you find that your team regularly leans in one direction or the other, encourage them to actively adopt a different mindset. A team of optimists could hold an anxiety party or pre-mortem to identify potential flaws in a plan, while a group of pessimists could spend more time in the “flare” portion of a brainstorm, creating and building on existing ideas rather than judging them.
2. Encourage psychological safety. Use meeting check-ins, 1:1s, team retrospectives, and other exercises to build psychological safety on your team. If everyone feels that they can openly share both their crazy ideas and their misgivings, you’ll have more productive discussions and get a realistic picture of the challenge at hand.
3. Be aware of how you reward people. Reflect on your behavior as a leader. Have you (perhaps subconsciously) surrounded yourself with optimists because you need to feel supported? Or are you the first one to shoot down ideas when they’re first proposed in a meeting? Your team is keenly aware of what behaviors are rewarded and punished, and this feedback, more than any motivational speech or candor-building activity, will influence how they act.